PostgreSQL Query Optimization: The Ultimate Guide to Building Efficient Queries

© Henrietta Dombrovskaya, Boris Novikov, Anna Bailliekova 2021

H. Dombrovskaya et al.PostgreSQL Query Optimizationhttps://doi.org/10.1007/978-1-4842-6885-8_2

2. Theory: Yes, We Need It!

Henrietta Dombrovskaya¹  , Boris Novikov² and Anna Bailliekova³

(1)

Braviant Holdings, Chicago, IL, USA

(2)

HSE University, Saint Petersburg, Russia

(3)

Zendesk, Madison, WI, USA

 

In order to write performant queries, a database developer needs to understand how queries are processed by a database engine. And to do that, we need to know the basics of relational theory. If the word “theory” sounds too dry, we can call it “the secret life of a database query.” In this chapter, we will take a look at this “secret life,” explaining what happens to a database query between the ...